An investigation into the effect of soil-foundation interaction on the seismic performance of tunnel-form buildings

Abstract

Great weight and stiffness can potentially intensify the forces induced to the tunnel-form buildings during seismic events. To overcome the adverse effects of these two parameters on the seismic reliability of buildings benefitting from this structural system, it appears critically essential to account for the soil-structure interaction (SSI) in the modeling process. Accordingly, this paper aims to assess the level of seismic performance as well as the safety condition of buildings against sliding and overturning phenomena. For this purpose, the soil underlying two tunnel-form buildings with 5 and 10 stories was modeled using the linear springs and then, the analysis results were captured for two cases of rigid and flexible base. Based on the results, as the building height and earthquake intensity increases, the SSI effects on the structural responses such as the shear forces and storey drifts and location of damage initiation became profounder. Comparatively, probability of reaching the primary damage levels along with sliding and overturning increased by at least 30 and 10%, respectively in the case of flexible base. In sum, it is concluded that in seismically active areas formed by soft soil, the SSI effect can hinder tall buildings from achieving the predefined performances.